/*!	 spiralgradient.cpp
**	 Implementation of the "Spiral Gradient" layer
**
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2011 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <synfig/localization.h>
#include <synfig/general.h>

#include <synfig/string.h>
#include <synfig/time.h>
#include <synfig/context.h>
#include <synfig/paramdesc.h>
#include <synfig/renddesc.h>
#include <synfig/surface.h>
#include <synfig/value.h>
#include <synfig/valuenode.h>
#include <synfig/cairo_renddesc.h>

#include "spiralgradient.h"

#endif

using namespace etl;
using namespace std;
using namespace synfig;

SYNFIG_LAYER_INIT(SpiralGradient);
SYNFIG_LAYER_SET_NAME(SpiralGradient, "spiral_gradient");
SYNFIG_LAYER_SET_LOCAL_NAME(SpiralGradient, N_("Spiral Gradient"));
SYNFIG_LAYER_SET_CATEGORY(SpiralGradient, N_("Gradients"));
SYNFIG_LAYER_SET_VERSION(SpiralGradient, "0.1");
SYNFIG_LAYER_SET_CVS_ID(SpiralGradient, "$Id$");

SpiralGradient::SpiralGradient():
    Layer_Composite(1.0, Color::BLEND_COMPOSITE),
    param_gradient(ValueBase(Gradient(Color::black(), Color::white()))),
    param_center(ValueBase(Point(0, 0))),
    param_radius(ValueBase(Real(0.5))),
    param_angle(ValueBase(Angle::zero())),
    param_clockwise(ValueBase(false))
{
    SET_INTERPOLATION_DEFAULTS();
    SET_STATIC_DEFAULTS();
}

bool
SpiralGradient::set_param(const String & param, const ValueBase &value)
{
    IMPORT_VALUE(param_gradient);
    IMPORT_VALUE(param_center);
    IMPORT_VALUE(param_radius);
    IMPORT_VALUE(param_angle);
    IMPORT_VALUE(param_clockwise);

    return Layer_Composite::set_param(param, value);
}

ValueBase
SpiralGradient::get_param(const String &param)const
{
    EXPORT_VALUE(param_gradient);
    EXPORT_VALUE(param_center);
    EXPORT_VALUE(param_radius);
    EXPORT_VALUE(param_angle);
    EXPORT_VALUE(param_clockwise);

    EXPORT_NAME();
    EXPORT_VERSION();

    return Layer_Composite::get_param(param);
}

Layer::Vocab
SpiralGradient::get_param_vocab()const
{
    Layer::Vocab ret(Layer_Composite::get_param_vocab());

    ret.push_back(ParamDesc("gradient")
                  .set_local_name(_("Gradient"))
                  .set_description(_("Gradient to apply"))
                 );

    ret.push_back(ParamDesc("center")
                  .set_local_name(_("Center"))
                  .set_description(_("Center of the gradient"))
                 );

    ret.push_back(ParamDesc("radius")
                  .set_local_name(_("Radius"))
                  .set_description(_("This is the radius of the circle"))
                  .set_is_distance()
                  .set_origin("center")
                 );

    ret.push_back(ParamDesc("angle")
                  .set_local_name(_("Angle"))
                  .set_description(_("Rotation of the spiral"))
                  .set_origin("center")
                 );

    ret.push_back(ParamDesc("clockwise")
                  .set_local_name(_("Clockwise"))
                  .set_description(_("When checked the spiral turns clockwise"))
                 );

    return ret;
}

inline Color
SpiralGradient::color_func(const Point &pos, float supersample)const
{

    Gradient gradient = param_gradient.get(Gradient());
    Point center = param_center.get(Point());
    Real radius = param_radius.get(Real());
    Angle angle = param_angle.get(Angle());
    bool clockwise = param_clockwise.get(bool());

    const Point centered(pos - center);
    Angle a;
    a = Angle::tan(-centered[1], centered[0]).mod();
    a = a + angle;

    if (supersample < 0.00001) {
        supersample = 0.00001;
    }

    Real dist((pos - center).mag() / radius);

    if (clockwise) {
        dist += Angle::rot(a.mod()).get();
    } else {
        dist -= Angle::rot(a.mod()).get();
    }

    dist -= floor(dist);

    if (dist + supersample * 0.5 > 1.0) {
        float  left(supersample * 0.5 - (dist - 1.0));
        float right(supersample * 0.5 + (dist - 1.0));
        Color pool(gradient(1.0 - (left * 0.5), left).premult_alpha()*left / supersample);
        pool += gradient(right * 0.5, right).premult_alpha() * right / supersample;
        return pool.demult_alpha();
    }

    if (dist - supersample * 0.5 < 0.0) {
        float  left(supersample * 0.5 - dist);
        float right(supersample * 0.5 + dist);
        Color pool(gradient(right * 0.5, right).premult_alpha()*right / supersample);
        pool += gradient(1.0 - left * 0.5, left).premult_alpha() * left / supersample;
        return pool.demult_alpha();
    }

    return gradient(dist, supersample);
}

float
SpiralGradient::calc_supersample(const synfig::Point &x, float pw, float /*ph*/)const
{
    Point center = param_center.get(Point());
    Real radius = param_radius.get(Real());

    return (1.41421 * pw / radius + (1.41421 * pw / Point(x - center).mag()) / (PI * 2)) * 0.5;
}

synfig::Layer::Handle
SpiralGradient::hit_check(synfig::Context context, const synfig::Point &point)const
{
    if (get_blend_method() == Color::BLEND_STRAIGHT && get_amount() >= 0.5) {
        return const_cast<SpiralGradient*>(this);
    }

    if (get_amount() == 0.0) {
        return context.hit_check(point);
    }

    if ((get_blend_method() == Color::BLEND_STRAIGHT || get_blend_method() == Color::BLEND_COMPOSITE) && color_func(point).get_a() > 0.5) {
        return const_cast<SpiralGradient*>(this);
    }

    return context.hit_check(point);
}

Color
SpiralGradient::get_color(Context context, const Point &pos)const
{
    const Color color(color_func(pos));

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        return color;
    } else {
        return Color::blend(color, context.get_color(pos), get_amount(), get_blend_method());
    }
}

bool
SpiralGradient::accelerated_render(Context context, Surface *surface, int quality, const RendDesc &renddesc, ProgressCallback *cb)const
{
    RENDER_TRANSFORMED_IF_NEED(__FILE__, __LINE__)

    SuperCallback supercb(cb, 0, 9500, 10000);

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        surface->set_wh(renddesc.get_w(), renddesc.get_h());
    } else {
        if (!context.accelerated_render(surface, quality, renddesc, &supercb)) {
            return false;
        }

        if (get_amount() == 0) {
            return true;
        }
    }

    int x, y;

    Surface::pen pen(surface->begin());
    const Real pw(renddesc.get_pw()), ph(renddesc.get_ph());
    Point pos;
    Point tl(renddesc.get_tl());
    const int w(surface->get_w());
    const int h(surface->get_h());

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        for (y = 0, pos[1] = tl[1]; y < h; y++, pen.inc_y(), pen.dec_x(x), pos[1] += ph)
            for (x = 0, pos[0] = tl[0]; x < w; x++, pen.inc_x(), pos[0] += pw) {
                pen.put_value(color_func(pos, calc_supersample(pos, pw, ph)));
            }
    } else {
        for (y = 0, pos[1] = tl[1]; y < h; y++, pen.inc_y(), pen.dec_x(x), pos[1] += ph)
            for (x = 0, pos[0] = tl[0]; x < w; x++, pen.inc_x(), pos[0] += pw) {
                pen.put_value(Color::blend(color_func(pos, calc_supersample(pos, pw, ph)), pen.get_value(), get_amount(), get_blend_method()));
            }
    }

    // Mark our progress as finished
    if (cb && !cb->amount_complete(10000, 10000)) {
        return false;
    }

    return true;
}

bool
SpiralGradient::accelerated_cairorender(Context context, cairo_t *cr, int quality, const RendDesc &renddesc_, ProgressCallback *cb)const
{
    RendDesc	renddesc(renddesc_);

    // Untransform the render desc
    if (!cairo_renddesc_untransform(cr, renddesc)) {
        return false;
    }

    Point pos;
    const Real pw(renddesc.get_pw()), ph(renddesc.get_ph());
    const Point tl(renddesc.get_tl());
    const int w(renddesc.get_w());
    const int h(renddesc.get_h());

    SuperCallback supercb(cb, 0, 9500, 10000);

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        cairo_save(cr);
        cairo_set_operator(cr, CAIRO_OPERATOR_CLEAR);
        cairo_paint(cr);
        cairo_restore(cr);
    } else {
        if (!context.accelerated_cairorender(cr, quality, renddesc, &supercb)) {
            return false;
        }

        if (get_amount() == 0) {
            return true;
        }
    }


    int x, y;
    cairo_surface_t *surface;

    surface = cairo_surface_create_similar(cairo_get_target(cr), CAIRO_CONTENT_COLOR_ALPHA, w, h);

    CairoSurface csurface(surface);

    if (!csurface.map_cairo_image()) {
        synfig::warning("Spiral Gradient: map cairo surface failed");
        return false;
    }

    for (y = 0, pos[1] = tl[1]; y < h; y++, pos[1] += ph)
        for (x = 0, pos[0] = tl[0]; x < w; x++, pos[0] += pw) {
            csurface[y][x] = CairoColor(color_func(pos, calc_supersample(pos, pw, ph))).premult_alpha();
        }

    csurface.unmap_cairo_image();

    // paint surface on cr
    cairo_save(cr);
    cairo_translate(cr, tl[0], tl[1]);
    cairo_scale(cr, pw, ph);
    cairo_set_source_surface(cr, surface, 0, 0);
    cairo_paint_with_alpha_operator(cr, get_amount(), get_blend_method());
    cairo_restore(cr);

    cairo_surface_destroy(surface);

    // Mark our progress as finished
    if (cb && !cb->amount_complete(10000, 10000)) {
        return false;
    }

    return true;
}